Vaccination syringe



March 16,, 1948. G, N. OVERTON VACCINATION SYRINGE Filed Jan. 19, 1946 N Q T R E V 0 N P M R O N E 6 R o E G Patented Mar. 16, 1948 UNITED STATES PATENT OFFICE VACCINATION SYRINGE Indies Application January 19, 1946, Serial No. 642,316 In Great Britain July 26, 1945 3 Claims. 1

This invention relates to improvements in vaccination syringes, and the principal object of the invention is to provide a syringe which aflords the operator easy and definite control of the quantity of lymph used in each operation, eliminates any wastage of lymph and facilitates the performance of a large number of operations in a relatively short time.

A further object of the invention is to provide a syringe, the parts of which are so constructed and arranged that, when the syringe is held in the hand of an operator in a suitable manner for performing vaccination, the operations necessary for causing lymph to be drawn into the syringe through the needle and to be expelled at the needle point can be effected by the hand holdin the syringe without substantially altering the position of the syringe.

One embodiment of the invention is illustrated in the accompanying drawing, in which Fig. 1 is a side elevation of the syringe and Fig. 2 is a sectional side elevational of the same on a larger scale with part of the needle broken away.

The syringe illustrated may have an overall length of about and is constructed as follows. A standard syringe needle I is mounted firmly by its externally tapered butt end 2 in the taper bore 3 of a metal sleeve 4, which forms a lower extension of the cylinder member 5 described below, the taper bore being at right angles to the axis of the cylinder. Firmly fixed into the butt end of the needle and in line with the needle, is a tubular lymph reservoir 6 of glass. The bore of this tube 6 is several times that of the bore of the needle I but is preferably such that the lymph will, owing to surface tension fill the cross section of the tube over at least a part of its length, even when the tube is held horizontally. The tube is preferably graduated in cubic centimeters (not shown in the drawing).

Over the tapered outer end of the tube 5 is tightly fitted a metal cap 1, the head of which is bored and has a bored extension 8, over which is fitted one end 9 of a rubber tube ID of good quality. The rubber tube is bent back on itself in an easy curve and is passed over the thickened end of a suction tube II of metal mounted at its other end in the wall of the cylinder 5 and making connection with the interior of the cylinder near the floor of the cylinder. The suction tube l l and the lymph reservoir 6 lie in the same vertical plane, but they approach one another in the direction of the cylinder 5.

The piston and cylinder device, which is positioned about mid-way of the instrument, or rather nearer the needle point, comprises the cylinder 5, beneath the floor of which is the sleeve member 4, in the tapered bore of which is mounted the butt 2 of the needle. The cylinder is threaded externally to co-operate with an internally threaded cap i2 capable of being screwed downwards and upwards over the cylinder. The lower portion of the cap i2 is milled externally at [3 to facilitate finger and thumb operation and the top of the cap has a flange, also milled at the edge 5, for use when the syringe is to be charged with lymph.

The piston I6 is attached to the underside of the head of the cap by means of an upward extension ll, with which engages a screw l8 which passes centrally through the head of the cap and draws the piston extension i1 close against the head. The extension at the upper end of the piston may have a reduced portion 59, which 10- cates in the bore of the head, The piston l6 fits the cylinder 5 snugly and has a peripheral groove 20 for the retention of a lubricant. The lower end of the piston may have a slot cut in it to enable it to be held fast when the screw I8 is being tightened.

To charge the glass reservoir tube 6 of the syringe the piston 16 is brought to its lowest position in the cylinder 5 by turning the milled flange 15 of the cap, and thus expels the air from the cylinder, the sterilised point of the needle is immersed in the phial containing the lymph, and the piston is raised by turning the cap in the reverse direction. The suction action of the piston will thus draw the lymph into the reservoir tube 6. Although the reservoir may be graduated, .a circle in red may be marked near the outer end of the reservoir, beyond which the tube 6 should not be filled, for it is not intended that the lymph should pass beyond the reservoir tube and come in contact with the rubber tube to. Subject to this the syringe will be charged with sufficient lymph to perform the number of operations immediately contemplated.

The charged syringe may be held in the hand the finger and thumb and the lymph applied to the scratch. Lymph is withdrawn slightly from 3 the needle point by screwing back the piston and the needle point is wiped clean on sterilised gauze or cotton, The operator, while still holding the syringe, is ready for the next operation.

There are only two parts of the device described which need to be sterilised from time to time, viz. the lymph reservoir 6 and the needle 1, and they can be readily detached for that purpose. The piston, cylinder and rubber tubing should be kept clean but they will not require sterilisation, as they do not come in contact with the lymph.

I claim:

1. A vaccination syringe, comprising a hollow needle, a tubular lymph reservoir extending from the butt end of the needle and communicating at one of its ends with the bore of the latter, a

cylinder mounted on the syringe adjacent the butt end of the needle and disposed laterally of the axis thereof, a piston arranged for sliding movement in said cylinder, a screw-threaded member located close to the butt end of the needle, connected with the piston and engaging With a screw-threaded portion of the cylinder, and a tubular connection between the other end of the lymph reservoir and said cylinder, the lymph alternatively being drawn into the reservoir through the needle or expelled at the needle point by rotating said screw-threaded member in one direction or the other to cause said piston to move in said cylinder to enlarge or reduce the air space therein which is in communication with the lymph reservoir.

2. A vaccination syringe, comprising a hollow needle having a thickened butt end in the form of a tubular socket part, a tubular lymph reservoir having one of its ends fitted into and engaged in said tubular socket part, a cylinder body having an externally threaded cylinder wall and a downwardly extending portion bored transversely to the axis of the cylinder and detachably fitted over the thickened butt end of the needle, a suction tube connecting the other end of said lymph reservoir wih the interior of the cylinder, an internally threaded cap member fitted over the cylinder body and engaging with the externally threaded portion thereof, and a piston fitting within said cylinder and having its outer end connected to the crown portion of said cap memher.

3. A vaccination syringe, comprising a hollow needle having a thickened butt and bored out internally and having its internal and external surfaces tapered in the direction towards the needle point, a tubular lymph reservoir composedof transparent material and having an externally tapered end detachably engaged in the tapered bore in the butt end of the needle, a cylinder body having an externally threaded cylinder wall and a thickened base portion formed with a tapered bore extending at right angles to the axis of the cylinder, said cylinder body being detachably mounted on the butt end of the needle by engagement of the internal surface of the tapered bore in its base portion with the external tapered surface of the needle butt end, a suction tube mounted by one of its ends in the cylinder body and communicating with the interior of the cylinder thereof, a nipple detachably fitted over the other end of the lymph reservoir, a flexible conduit interconnecting the other end of said suction tube with said nipple, an internally threaded cap member fitted over the cylinder body and engaging with the externally threaded portion thereof, and a piston fitting within said cylinder and having its outer end connected to the crown portion of said cap member.

GEO. N. OVERTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 792,836 Loveless June 20, 1905 FOREIGN PATENTS Number Country Date 123,271 Germany Sept. 24, 1901 

